Abrading



H. W. HILL Nov. 28, 1933.

ABRADING 3 Sheets-Sheet l Filed Feb. 10, 1928 Ill/2b 2*: i: y, I

Q Harrgm Hill Nov. 28, 1933. H. W. HILL ABRADING Filed Feb. 10, 1.928

, 3 Sheets-Sheet 3 Patented Nov. 28, 1933. h r

v ABRADING iiarry Hill,-Son-thbridge; Mass; a s sig -nor.to

American .Optical Company,

Mass, a voluntary association of Massachu- Application'February l'o, esa-a1 2523 1 28 Claims. (01. 51 -111) ,flThis invention relates to improvements in tabrading and has particular rete'rence to improved 'ahrading apparatus in which a plurality of articles t'o hefabrade'd are loosely 'held in a holder during the'abrading operation. It also has particular reference t'oan improved process Iorfcarrying out this "abradi'ng. I

The principal object of the invention' isto provide improved means for surfacing curved. surfaces on a plurality of articlea'to be abraded whichare loosely held 'in awo'rk holder. Another object of the invention is fto .'provide improved means by whieh lbothsur fa'cesoi an article may be "abraded "to curved surfaces while held loosely in the workjholder.

,Another object of the invention is 'to provide means for imparting motion to "thefwork holder whereby the linesof abrasion are br'okenfup,'that is, are not repeated in one cycle jafter another.

Another 'objectf'bf the'invention-is to provide improvedm'eans for rotating and gyratingf the w'orkholder. v 3 t,

Another object of the invention "islto provide a work'holder fora plurality.of'articlesto be abraded which will permit of surfacin'g thearticl'e to be abraded to a'curved surface. I,

Another object of the invention is" to provide improved means by which all of the articjles to be abraded will be'ab'ra'de'cl to an equal and'like thickness. i v I Other objects and advantages of the' invention should become apparent from the ifoll'owing description taken in"conhection with "the .accoinpanying drawings; and it"will" be ap arent that many changes may bem'ad'e in" the details offconstruction, arrangement of parts "and steps of the process without departing from the spirit of the invention as set 'forth in the accompanying claims. I, therefore, dofno'twish to' be limited to me exactdisclosures made as the preferre'd forms only have been'shown 'by way of illustration.

Referring to the drawings: I

"Fig. 1 is'a partial elevation in'cross section showing one adaptation of thein'vention;

Fig. 2 isa similar partial elevation of amod ification;

"Fig.1; is a partiar'cross section of the article to "be" abradedonithe device of Fig. 1f showing that the bottom surfaceis the 'onejto"be'ahraded;1

Fig. 5 is a"similaricross:sectionshowing thearticle that is tobe abraded" onflthe device of Fig. 2,"the bottom surface" 'beingthat which is-to be werrea upon;

crosssection of another modi- .ject ofthe"present QinVentiOnfto retain all "the duce each er Fig. '6. is a; similar cross section showing 'the article to be *producedin the device -of Fi'g 3, V the underfsurface being the surf ace worked upon;

Fig. *7 is "a longitudinal cross section of still an; other modification; f v

"Figi- Sis a or s section o'f'thear'ticl'e to be3px-0- duced on the device of Fig. 7, both top'a'ndhottomsurfa'ces bing workedupon; 4

FigfQjis-a-crosssection-on line 9-'9 of Fig."?; Fig-10 15:31 cross section on line 10- 10 of'Fig. 7;

' Figjl l is a top-or plan-view-of thework 'holder Fig. 7 13 is afragnientaryplan view or f1 'ln' theprior art it h'as' beenbe'lieved that-in the abrading of surfaces-pp articles-which}are-loosely held in a so-calledring work-holderionly'plain or flat surfaces could be produced. 'There'iare a great manyf-artieles that requiresurfacing-tom curvature, [and it lag-"therefore, the principal ob-i advantages o'f the prior art fsurfacingfl'df articles whereihablurality of these' artieles irra'y be loose lyheldin theworkho1der,*antliat the sametime extend 'thoee' advantages' and others :to -"the producti'on" of "-a pi'umntyzer articles simultaneously, all of which shall have curved-surfaces either-"on ones-ide-or. en'bothei'desthereof. i

Referring' to the drawings; wherein similar refere'nee 1 characters fden'ote .-"corresponding-parts throughout, the"'articles' 1 to be abrade loosely carriedin openings ZfFig. llfin a v like work? ho-lderf3; {This "work" holder fb flatas shown ir Figl l, conve as'-shown-in r g- 2, or. concave as-shown 'Ffig T3 and '7,"depending upon the? character of the surface" WhiChfiSjfOifb placed upon the article lfthatfis tofbeyabraided.

As the apparatus depends j somewhat upon f the nature ofj' the surface tolbe abraded, I wi11-. des'ribethe construction and operationsltoupro 5 the articles set-iforth inlnigsaa 5;;6

V f t I The-bottom surface 4. of the article ll showrhin Fig; 4 is the: surface, that is -to be abraded jrrlthe apparatus shown in -Figgl. The:'-articles-.1 ;toebe abradedare placed i-n.-the.-;openi-ng .2wofvthework holder -ring 3. ;-The surface i4 j-whichristoiibe abraded is placed in 'contact with thezlabradmg wheel S y-which abradingtwheeleis; carriedsbyithe 1 support- '6' "which islkeye'd; tosthe ahollowe 'shaft 'i carried' py" thef fraimefi8, mounted on 'the 'shaft g afld d'rivem by the pulley"- oand -bew 11.1; Over the greene -11s placed the weight ringiz; which throughth'e'action ofgravity 'suppl-ies th abiiad m ing friction to the articles 1 on the abrading wheel 5, and'at the same time works as a regulator for the thickness of the various articles 1 which are being abraded, as it will be apparent that the weight at the initial start of thegrinding'operation will bear only on the highest or thickest articles in the work holder 3.

. having a plurality of openings'2 to carry the with the ring gear 28 as shownin Fig. 9.

articles 1, and is secured to the disc 19 by the screws 20or other means. In the disc 19 are the openings 21 into which the pins 22 project.

' weight 12 whereby the weight takes the'movement ofthe plate 19. g I

The operation is as follows: The grindinglap 5 is driven bythe pulleylflhaving a circular motion. The shaft 9 is driven by the pulley 29 which rotatesv the disc 26, which causesthe gears 27 to rotate around the track of the rack 28, which rack 28 in turn causes the gears 2'7 to rotate, turning thepin 25, which rotates the crank plate 23 carrying the pins 22 in the plate 19, causing the plate 19 and the weight 12 to travel therewith. The plate 19 carries the lens holder 3; thus it will be seen that the lens holder- 3 has a rotary and a gyratory movement and is of differentspeed than the rotation of the lap or abrading wheel 5, thus causing what is known as a break-up motion of the articles over the lap. In this way it will be seen that the under surface 4 of the article 1 is abraded. In removing the work the weight 12 may be lifted by the bolts 13 as has been described above and the finished articles removed and new 9 articles placed therein.

The device of Fig. 2-isfor abrading the surface 4 of Fig. 5, which is a concave curved surface. The construction and operation of the device of Fig. 2 are practically identical with that of Fig. 1 except that the. surface '32 of the lap 5 has a convex curvature and the under surface 33 ofv the weight 12 has a concave surface. The work holder disc 3 is also a concave-convex curved disc. The operation and construction of the device, are otherwise identical with that of Fig. 1.

with the exception that the surface 34 of the lap 5 is a concave surface. The under surface 35 of the-weight 12 is a convex surface and the work holder disc 3 is a concavo-convex surface having the convex surface on the underside. V

Fig. 8 shows the surfaces 4 which are to be abraded by the device of Fig. 7, namely, a concave surface on the top and a convex surface on the bottom. The means for'driving the lap 5and the work holder disc 3 is practically identical with thatvdescribed above for the otherdevices. The lap 5 has a concave surface 36 and the work holder disc. 3 is a concavo-convex disc asabove with the convex surface downward. In this instance, how- The ever, the weight 12 is held stationary and has the abrading surface 37which is a concave surface. The weight 12 is supported by the frame 18 by means ofthe shaft 38 carrying the ball member 39 and the shank 40, to which the weight 12 is non-rotatably secured by the pin 41. The shaft 38 is keyed to the frame -18at 42 and is slidably mounted therein. The disc 3 is supported by the rods 43 secured to a ball socket member 44, said rods being pivoted at 45 to the member 44. The work holder disc 3 is secured to the plate 46, said plate 46 having the openings 47 which fit over the pins 48 which are carried by the crank disc 23. This plate, therefore, has a movement like that of the weight 12 in Fig. 1 imparted to it through the rotation of theshaft 9. The pins 48 have a ball end so that the plate 46 may have a universal rocking movementthereon. In operation the lap'5 is rotated as before. The work holder plate has the circular and gyratory movement of Fig. l, but the. weight 12 is held stationary-,-- as described, having an abrading surface '37 operating on the upper surface'of the article 1. The

weight 12, while held stationary, may rideup and down with the shaft 38 to accommodate for the thickness of the article and the abrading away thereof. The rods 43. merely act as a support for the lens holder 3. This support rocks or operates about the center of curvature of the work holder 3'although' the work holder 3 might be used without the rods 43 and the supports 44.

From the foregoing description it will be seen that I havev provided simple, eflicient and economical means for producing either flat or curved surfaces upon a plurality of articles loosely held in a moving work holder well adaptedto carryout and obtain all the advantages of the process and the apparatus.

Having described my invention, I claim:

.1. In a device of the character described, a curved faced'lap, a curved work holder adapted to fit the curve 'of the lap and hold the work on the 1ap,universal joint connectionson the curved work holder, crank means having universal joint connections engaging the univeraljoint connecter of the laps, and means to rotate the crank means bodily about the center of the laps to cause the curved work holder to move over. the curved faced lap substantially about the center of the curve on the lapj 2.,In a device ofv the character described, a rotatable lap having acurved abrading' surface,

means to rotate the lap, awork holder having l substantially the same curvature as the lap and having a plurality'of openings adapted to loosely hold the articles to be abraded in position .onlthe lap, and means to simultaneously rotate the work holder'and to give the same a gyratory motion in a path of 'the curvature of the lap to move the articles of work over the lap.

3.- In a device of the character described, a rotially the same curvature as thelapandspaced tions on the curved work holder, means to'rotate the crank means in a path eccentric to the cenaw-e92,

therefrom, a work holder of substantially the samecurvaturebetweenthelap ,andweightine'in f ber, and' means to rotate Ta'nd gyrate the work holder in "a path substantially of the curvature of the lap and weighr'member.

5. In adevioe of the character described, a

v rotatable lap having a curved "abrading' surface,

means to rotate the l'apfa' curved work holder having substantially the same "curvature" as the lap and having a pluralityof 'openings adapted to looselythold th fWQrk in place on the lap, "a1 second'lap opposite the first lap havinganabrad. ing.surf ace, substantially concentric with" the abrading surfaceof the-first lap and separated therefrom by the 'work holder," means for 'non-" rotatably supporting the'seco'nd lap, and means for'jrotating and gyrating the work holder'between'thetwo laps in apath'of substantially'the curvature of the laps to move the work over the abradin'g surfaces ofthetwo laps to abrade the o9p0sitefsides Of the work.

" SJIn' a device of the character described, .an

annular lap, means to rotate the lap, a second lap opposite the first lap, a work holder between the two' laps having portions extending beyond the outer edges of the laps, a support forthe second lap, 'auniversal joint connection on the support, and tie rods'conne'cting portions of the universal connection and the extending portions 3 of the work holder;

'7. In a device of the character. described, alap, asecond lap opposite the first lap, awork holder between the laps having portions extending be yond the outer edges of the laps, a support for the second lap, a'ball joint on'the' support, a b'all joint collar engaging the ball and tie 'members connecting the collar and extending. portions of theworkholder;v i

8. In a device of the character described, a

laprasecon'd lap oppositethe first lap, a work holder between thelaps having portions extendin'g beyond the outer edges of the laps, a su port on thesecond lap mounted to allow the second lap to be moved towards and away from the first lap but held against rotation, a ballfjoint-on' the support, a ball jointlcollar engaging'the ball, and 1 tie members connecting the collar and the exitend- I ing portions of'thew'ork holder. c

9. In adevice of the character described, a lap, a second lap opposite the firstlap, a workfholder between the 'lapjsjuniversal joint connections on the work'holder, crank means having universal joint" connections'engaging the universal joint connections on the work'holder, means to T rotate ,the'craink means ina path eccentric to the center of the laps, and means to rotate the crank bodily about the center of the laps. a l0. Ina device of the character described, a

lap havin'g'a curved surfacing face, a second lap means having a curved surfacing fa-o e portion opposite the first lap,.and a curved work holder between the laps 'movablysupported so that its center of movement is locatedsubstantially at its center of curvature, the said laps being formed with contra generic curved surfaces which engage andabrade both sidesof the work simultaneously.

11. In a device of the character described, a

' curved lap, a weight member having substantially the same curvature as the lap and spaced therefrom, a work holder of substantially the same curvature located between the lap and weight member and means to move the work holder to give the same a movement over the lap so that the work will be carried over the lap in an irregular path to prevent the repetition of lines 'mem ber, iiitei engajging' means .like' 'rrfie be f i nart,

reduced;

likemeinberto impart'anf equal era-sure the i was we erase re ie 1 lap, v, 7 v o '13. In a device" of the'character described, a. curved lap, aweight-like memberh" stantially'the ame' curvet re as the lap, r Holder Ofsubstahtiallyftheisahii urvatur'e he; lapfandweiglit-like member ahd'locatedbet' tr em and eansito m 'e the k: 1'

causethe "workft' mo ""the ab" ding f r lap?" v/fi ht" llkefmeinberf'and work holding inemb'erj i 'mean or. im r i f'irre ul to'tliework'holderandinte ngage' jw g m'em rft reate, u'ab adi e acti n said rmit i j h, we ehtl 0i plurality of 'pieces'of *worksimultaneously duri the abrading operation.

1" 5."In a' device dijthe character described, a

lap, a weight nee: memberffspacedf from tire-lap; 119

work holding" m ans for"holding'i a a'lit r pieces of ffwork between theflapfanfd' weig f im' fii fil g I d m an t een 1 1. lap aridflweightdike nicmbel" .andf fiieans for, i i-T" arting arifirregula'rlmovementit ,the work holder is n i nsi eedlwe ht l kememb ji'c a e 7 an abrading;aetion onthework, saidfintere g'a ns id mean permi ti g t ef'we' t ke m 'm=5 ber to' move downwardly to first engage and ex pressure on th"" pieces 01.

thicknesses and cau'sejthefsame' to abrade quickly and their permit the weightilikei member to d scend and exert an equal 'pressure c'njfall of pieces of work simultaneously and cans the s ne'sses after'the th c' 'es t pieceswor I h M '16; 'Inja device of the character describedfa laphaving a curved abradgfsiirf "afwei' ht ken e rf afi s. ubstantia l a re l h la d tem: th from; k ld n member p if b d fns lu ali 91; pieces of work between the curved laparid ,W'eightf like 1 member, intereng'ag'ing means" between .7 the weight like member and work holding member and means" for imparting an irregular movement td'the work holder andfintereng'aged; wei'g m be -i9 r a ab adin a ti eon I id interen'e s ne man 'i erm ti i t erg plurality of pieces of work simultaneously during: the abrading operation. 4 I

17. In a device of the character described, a lap having a curved abrading face, a weight like mem- 1 her having substantially the same curvature as 14.5

the lap and spaced therefrom, curved work holding'means for holding a'plurality' of pieces of" work between the curved lap and weight like member, interengaging slide means betweenthe lap and weight like member and means for im 15%;. I

"work off-the reatet'rza,

parting an irregular movement to the work hold-.

er and interengaged weight like member to create an abrading action on thework, said interengaging slide means permitting the weight like member'toimove downwardly to first engage and exert pressure on the pieces of work of the greatest thicknesses and cause the same to abrade quickly and then to permit the weight likememher to descend and exert an equal pressure on all of said pieces of work simultaneously and cause the said pieces to be'abraded to equal finished thicknesses after the thickestpieces of work have been reduced. 7 v

18. A lapping machine comprising a pair of spaced laps. which have opposed surfaces shaped as spherical zones, awork cage mounted between 'the laps and. shaped to move therebetween, and mechanism for revolvingthe cage and the laps relatively and meanscontrolled' by a lap to rock the cage laterally during such relativdimovement. a 1 V 19. A lapping machine comprising two opposed laps having concave and convex surfaces respectively which'are shaped as spherical zones, means 'torotate 'one'of the laps, a work cage shaped to move'between the laps and arranged tohold a.

plurality of workpieces in contact with both'laps ahd'means torevolve the work cage relative to y the laps with a compound motion and permit it torock laterally so that the work pieces may fol-f nection between the mechanism and the cage which permits the work to move with a compound motion over the surfaces of the abrading members and be abraded thereby.

21 A lapping machine comprisingtwo opposed" abrading laps having concave and convex surfaces respectively, each of which is shaped as aspherical zone, means to revolve one of, the laps, a workcage having a portion shaped as a spherical zone which is arranged to hold a plu rality of work pieces in contact with both of the laps and to move therebetween and drivingmeche.

ani'sm including a revolved driving pin'which is connected to said cage through a universal joint, serving to cause the work pieces tomove across the surfaces of the laps with a compound lateral and circumferentialmotion and be abraded thereby.

22., A lapping machine comprising two opposed annular laps having concave andconvex surfaces respectively which are shaped as' spherical zones, a work cage shaped to hold aplurality of work pieces therebetween, a crank pin connected to said'cage by a universal joint,'meansto rotate said crank pin and means to revolveisaid rotate ing'means about a central axis and thereby move the work pieces over the laps with a compound gyratory motion. I

23.The"method of making a lens' consisting in engaging the opposite faces of the lens with curved abrading surfaces, confining, the lens to prevent free movementthereof and relatively moving the confined lens and said surfaces positively to abrade both faces thereof simultaneously.

. 24. The method. of lapping a curved article which consists in supporting the article and positively rotating it while causing it to be abraded on its opposite faces simultaneously bypabrading'members having surfaces shaped as spher ical zones; 7

25. The method of making lenses which consists of mounting in spaced relation two laps I, having opposed concave and convex surfaces shaped as spherical zones, supporting alens between'the laps with the opposite faces of the lens engaged with the laps, and relatively moving the support for the lens andthe surfacesof the laps engaged by the fac'esgof the lens in the support. 1

26. A lapping machine having, in combination;

a concaved'lapanda'convexe'd lap mounted in spaced relation, means for supporting aplurality of work pieces between the laps'with the 0pposite faces" thereof engaged with the lapslrand mechanism for relatively moving said means and the laps to transfer the work pieces over the surface of the laps in a series of differential noncircular orbital paths successively,

27. Ailapping machine comprising two opposed laps having annular lapping surfaces concentric during the lapping operation, and locatedone above thefother, which do not lie inparallel.

plane's, but are shaped to' contact withropposite elementsof the workpieces therebetweemawork cage arranged to holdthe opposite sides of a plurality of, work pieces inoperative contact with and movable relative to the laps, the lapsand cage being so I arranged that the work pieces maybe both revolved and'moved laterally to lap the same,-and means including'a driving'mechanism connected to the cage to cause the cage to revolve and rock laterally and produce such lapping movement of the work pieces.

"28. A machine for making a-lens having .a concavo-convex surface, comprising two opposed abrasive members provided; with surfaces which are spherical zones corresponding with the curved surfaces of the finished lens, a lens supporting cage movable therebetween, and means to rotate and gyrate said cage with a rocking motion in such a manner that the work will move through an everchanging path between said abrasive members and be abraded upon both a sides simultaneously and'caused to conform with s the surface curvatures of the opposed laps.

imam! w. HILL. 

